Sannieboy

To correct you on your terminology. The idlers are the components that support the belt and the pulleys are what drive the belt and allow the belt to change direction. Non driven pulleys can also be referred to as idler pulleys.

Typically there is only one pulley that is used for a drive pulley but there are cases where more than one pulley is driven. It all depends on the design of the system. Motors are typically coupled together with the reducer shaft. There are also installations where you can have v-belt sheaves between the motor and the reducer. The reducer can be coupled to the drive pulley shaft or can also be shaft mounted. Another term for a shaft mounted reducer is a hollow bore. In other words the shaft is slid through the reducer and a shrink disc is tightened around the shaft to clamp onto the shaft by applying the proper torque to the shrink disc bolts.

Maintenance of idlers is usually replace failed rolls and throw away. You would need to determine the labour component of repairing the roll verses the replacement cost of the roll. If labour is cheap then it may be more reasonable to repair if the problem is only bearings. But in case of shell wear the roll will be required to be replaced.

Other maintenance conciderations:

1 - Inspection of the belting itself;

cover wear, splice condition, etc.

2 - Oil analysis of the reducer.

3 - Belt tracking (is the belt running in the center of the idlers.)

I am sure other s will have additional comments.

Regards,

Gary Blenkhorn ■

Dear Mr. Sannieboy,

I will suggest you to look in to college library or contact the manufacturer of pipe conveyor in your country or in Europe and obtain routine leaflet / literature about this equipment. It seems you are not aware about this equipment. Coming to the point mentioned by you, please note :

- In a belt conveyor or pipe conveyor, the belt is always pulled by drive pulley.

- The idlers are for supporting the belt with material on carrying run, and only belt in return run.

- You can also visit some nearby plant and see the pipe conveyor.

- After you have certain basic knowledge about the equipment and various items in this equipment, only then will you be in a position to think about the maintenance or automatic maintenance.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Dear Mr. Sannieboy

Operation and Maintenance of pipe conveyor is similar to belt conveyor except pipe conveyor requires following important aspects

1.0 As pipe rotates due to misalignment belt corner comes in between rollers and some times belt is damaged.

2.0 In case of belt snapping it is not possible to vulcanize belt in pipe formation Zone . Belt is to be temporarily clamped and pulled to location where Belt is flat and vulcanizing is feasible

3.0 Over loading more than pipe cross-section will damage the complete conveyor

A R SINGH

. ■

Dear Sanneyboy,

Mr. Gary is very correct. But your last few lines - I am unable to understand.

Regards.

A.Banerjee ■

Hello,

If you consider replacement of belt also part of maintenance then this activity is more difficult in case of pipe conveyor compared to belt conveyor. For belt conveyor, the new belt can be easily placed or pulled on idlers. In case of pipe conveyor, the introduction of the new belt requires pulling of belt through idler circular rings like threading into many number of needles in series. For replacement, this may be mostly by attaching one end of new belt to existing belt end. This activity is likely to need comparatively more time and efforts. Maintenance / erection experts can provide more specific information.

Also new belt is likely to demand comparatively more power initially for some time? Can this be taken care by idle or partial capacity running for some time?

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling

System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

Is there any information for the wear patterns on these belt configurations? Do the upper rollers wear slower than the lower ones? Is there a procedure for balancing roller wear by sequentially rotating the rollers position in the frames?

It is all very well to drag a failed belt to the end where it can be spliced but is there enough room available to reasonably align the section? Is the remaining section of belt properly aligned within the idler sets during, and before this procedure?

These are rather treacherous machines on reflection and much work needs to be done on maintenance whether automatic or otherwise. ■

Originally Posted by johngateley

Is there any information for the wear patterns on these belt configurations? Do the upper rollers wear slower than the lower ones? Is there a procedure for balancing roller wear by sequentially rotating the rollers position in the frames?

It is all very well to drag a failed belt to the end where it can be spliced but is there enough room available to reasonably align the section? Is the remaining section of belt properly aligned within the idler sets during, and before this procedure?

These are rather treacherous machines on reflection and much work needs to be done on maintenance whether automatic or otherwise.

John

In answer to your questions and in my experience.

Yes there are wear patterns on pipe conveyors, Yes the upper rollers do wear slower but this is not the only cause of idler failure. When conveyor is in a straight line the bottom idler of 6 takes approx. 60% of load and the 2 bottom wing idlers take approx. 20% each the top 3 idlers are only lightly loaded with the belt rotating them so in this case loading is a factor. When on a curve say horizontal the 2 wing idlers on inside of curve take most load so life is effected by load factors, however over time other factors like weather moisture/dust ingress of seals etc are a factor, it is not normal to change idlers around systematically only to replace failed idlers.

Regarding splice's if a damaged or failing splice is observed then it is moved /powered to the head or tail end whichever is best for replicing on the underside at the tail or head end there is an area of open flat belt of 7-10m depending on pipe size also on very long systems some install periodic splicing stations where frame is opened to give flat belt. For a catastrophic failure (which is unusual) it must be pulled to these places. It is normal and very practical to align the belt.

Although with some incidents on pipe conveyor need a little specialist knowledge they are all doable and in my experience general maintenance with pipe conveyors is somewhat less than that of open trough belts. ■